基于盲反卷的耐火材料声发射源信号恢复研究

发布时间：2018-03-10 09:24

本文选题：耐火材料　切入点：声发射源信号恢复　出处：《武汉科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：耐火材料是一种炉衬材料，它广泛用于冶金、化工、石油、机械制造、硅酸盐、动力等工业领域，在冶金工业中用量最大，占总产量的50％～60％。耐火材料是否可靠直接关系到高炉的安全性和可靠性，因此，，有必要对耐火材料进行安全检测，这对于保障高炉结构安全和避免重大安全事、提高产品质量等等具有重大意义和应用价值。近年来，声发射技术和压电传感技术在状态监测和无损检测领域得到了广泛应用，已取得了突破和重要科研成果，本文在以往专家学者的研究基础上，采用盲反卷算法对声发射信号传播过程失真问题进行了研究，并用压电主动传感技术进行了验证，最后对该方法的适用性进行了分析。本文的主要研究内容有： (1)针对耐火材料声发射信号传播过程发生衰减、散射等失真问题，设计实验装置，基于传播路径为线性系统这一前提，由断铅信号模拟耐火材料声发射信号，采用盲目反卷积算法直接由接收信号对传播路径的冲击响应函数进行估计，设计滤波器恢复声发射源信号。 (2)对声发射信号传播路径的冲击响应函数进行盲反卷估计，发现对于不同的传播路径频响曲线存在差异，表现为高频成分衰减较低频快，此外由于声发射探头的谐振作用，频响曲线在150kHz处有明显峰值。 (3)设计实验验证盲反卷方法的可行性，利用压电陶瓷片产生频率及幅值确定的输入信号，由输入输出信号计算传播路径的传递函数，发现盲反卷算法在辨识未知的线性系统时具有一定可靠性，同时对盲反卷恢复的效果进行了实验验证。 (4)对耐火材料三点弯曲实验声发射信号进行盲反卷恢复，得到其能谱系数，对比恢复前后信号各频段的频率成分，为耐火材料损伤状态的准确判断提供参考。
[Abstract]:Refractory is a kind of lining material. It is widely used in metallurgy, chemical industry, petroleum, mechanical manufacturing, silicate, power industry and so on. Whether the refractories are reliable or not is directly related to the safety and reliability of the blast furnace. Therefore, it is necessary to carry out safety tests on the refractories, which is necessary to ensure the safety of the structure of the blast furnace and to avoid major safety incidents. In recent years, acoustic emission technology and piezoelectric sensing technology have been widely used in the field of state monitoring and nondestructive testing. In this paper, based on previous research by experts and scholars, the distortion problem of acoustic emission signal propagation is studied by blind deconvolution algorithm, and verified by piezoelectric active sensing technology. Finally, the applicability of the method is analyzed. The main contents of this paper are as follows:. 1) aiming at the distortion of acoustic emission signal propagation of refractories such as attenuation and scattering, an experimental device is designed. Based on the premise that the propagation path is linear, the acoustic emission signals of refractories are simulated by lead broken signals. Blind deconvolution algorithm is used to estimate the impulse response function of the propagation path directly from the received signal, and a filter is designed to recover the acoustic emission source signal. 2) Blind deconvolution estimation of impulse response function of acoustic emission signal is carried out. It is found that there are differences in frequency response curves for different propagation paths, which shows that the attenuation of high frequency component is faster than that of low frequency, in addition, because of the resonance effect of acoustic emission probe, The frequency response curve has obvious peak value at 150 kHz. The feasibility of blind deconvolution method is verified by designing experiments. The input signal determined by frequency and amplitude is generated by piezoelectric ceramic chip, and the transfer function of propagation path is calculated by input and output signal. It is found that the blind deconvolution algorithm is reliable in identifying unknown linear systems, and the effectiveness of blind deconvolution recovery is verified by experiments. (4) the acoustic emission signal of three-point bending experiment of refractories is recovered by blind deconvolution, the energy spectrum coefficient is obtained, and the frequency components of each frequency band of the signal before and after recovery are compared, which provides a reference for the accurate judgement of damage state of refractories.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ175.1

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